This disclosure relates to electrosurgical tools for use in performing surgery on a surgical site and, in particular, relates to electrosurgical pencils which can be held in one hand by a surgeon and which can be connected to a suitable power source.
Electrosurgery can be used for cutting tissue, coagulating bleeding or achieving a combination thereof using electrical energy which can be provided by an electrosurgical generator. Energy for the operation is applied to the tissue through a blade electrode held in a hand piece by a surgeon. To apply the energy, the electrosurgical (ESU) pencil is activated by the surgeon by pressing a switch which can be located on the hand piece. If a single finger switch is used, the switch may have one position for providing a certain level of energy to achieve cutting while a different position of the switch supplies a different energy waveform to achieve coagulation. The electrosurgical pencil can be constructed as a disposable unit that is only used for one operation.
Published US application no. 2007/0260239 to R. J. Podhajsky et al. describes an electrosurgical pencil having a variable control. The pencil includes an elongate housing with an electrocautery blade supported within the housing and extending distally from its front end. This pencil has an activation button supported on the housing. The housing has a blade receptacle located at its front end which can receive the replaceable blade. The pencil is coupled to a conventional generator via a cable attached to the rear end of the pencil.
U.S. Pat. No. 5,626,577 issued May 6, 1977 to G. A. Harris describes an ESU tool or pencil which has a non-conductive main housing on which is at least one actuating button to selectively control the electrical current from an attached cord. The housing forms in the elongate aperture or passage extending from an open front end. An electrode housing is mounted in the main housing and it closely receives a relatively short electrode which is said to be either disposable or reusable. An electrically conductive material surrounds the internal passage of the electrode housing to provide an electrical connection for the electrode. There is also an elongate conductive post extending down the center of the main housing and received within the post end of the electrode housing which is covered with a non-conductive insulating sleeve. The electrode housing can slide upon the conductive post to allow adjustment to the position of the electrode housing in relation to the main housing.
Published US application no. 2003/0088247 dated May 8, 2003 describes an ESU pencil with the main body portion forming a handle and a wire retaining passage defined in the main body portion. In the front end of the main body is an electrode-receiving opening in which an electrode tip is mounted. Use of the electrode is controlled by a single-pole double-throw rocker type electrical switch mounted on top of the housing and mounted on a small circuit board. An insulated wire enters the wire-retaining passage of the housing through a rear opening and is connected to one terminal of the switch.
There is a need for an improved electrosurgical tool for use in performing surgery, which can be made at a reasonable cost so that the tool can be disposable and which also allows the elongate electrode to be adjusted in its longitudinal direction so that it can be moved from a retracted position to any one of a number of extended positions during the course of a surgical operation.